Rupture discs have long proven their worth in industrial and scientific operations as safety devices. In comparison with safety valves, they have the advantage of responding virtually without inertia to pressure changes and being capable of opening large cross sections without delay.
There is a series of requirements for materials to be used to produce rupture discs. They must, in particular, have rupture values reliably reproducible, they must be easy to roll or otherwise form into sheets, and they should be corrosion resistant. Metals in the annealed, pure state and alloys are used to a great extent as such materials. Non-metals such as plastics, e.g. silicone rubber, are now increasingly being used for this purpose.
In practice it has been found that rupture discs do not always adequately withstand pulsating pressure loads. Such periodic pressure fluctuations occur, for example, if vessels are fed by piston engines. The rupture discs tend to vibrate, causing the disc material to display the effects of fatigue; in addition, the rupture values change after a period of greater or lesser duration.
Tests have been undertaken to counter the difficulties described. For instance, the relieving surfaces have been divided up, i.e. the rupture disc surfaces reduced and, to compensate for this, the number of relieving cross sections are correspondingly increased. Although this solution to the problem leads to success with regard to the mechanical stability of the rupture discs, it is technically complex and therefore not cost-effective.